I have two IRNs, both green, and both very different little birds!
The male (Raja) was a chick that I bred myself, and he is about 5 years old. He is a lovely bird, but is a 'one person' bird and tends to be terrified of strangers, and at best, tolerant of family members. He talks alot, but hasnt learnt any new words for a long time. his vocab is: wolf whistle, clicks, hello, good boy, what's up raj, 'ohh', mmmmmwa!, and my favourite is "hey raj".. "whats a pussycat say?"... "meow meow!". he loves his mirror and his favourite toy is a green felt soft toy with red hair (i think he thinks its the embodiment of his reflection..). he isnt a cuddly bird, but he steps-up very well and is great to handle, and never bites. Because I have been studying, I made the decision to get him a companion. Its a decision I dont regret one bit!
His arch-nemesis/best friend (depends what mood they are in

) is my baby female Sari. She was handraised by a breeder, and weaned early december (so she's about 9 months old now). She likes cuddles, and was a biter, and although she has been trained to resist the urge I still dont always trust her! She is mischevious, and bosses Raj alot. As Mikaela noted, baby ringnecks definately learn from older ringnecks! Sari knows most of Raj's vocabulary, although there are a few things she hasnt quite perfected yet. she is also yet to voice any new material of her own, but im sure its in the pipeline. Another thing she has learnt from Raj (unfortunately) is that all strangers are scary and must be screamed at... we are still working on this one!
Despite their differences, Raj and Sari get along famously (Raj even feeds her) and they are great pets.